My father has passed away. The notary handling the estate only shows me a copy of his will and informs me that the original is with another notary. Is this legal?

Yes. Only the notary who holds the will (to whom your father entrusted it) is the custodian of the original. As soon as he is informed of the testator’s death, he must immediately draw up a report of opening and condition of the will, specifying the circumstances of its deposit (Article 1007 of the French Civil Code). He then sends an authentic copy of this report to his colleague. The original will can only be consulted at his office.